The present invention relates to a coupling for use to join two members. More particularly, it relates to a coupling having a wedge part capable of wedging relative displacement of the two members to the left or right so that the two members can be coupled plainly, firmly and economically.
Hitherto, means to couple by impeding relative displacement between one member such as a rotating axis for instance and the other engaging member such as a gear, chain wheel or pulley, involves a keying or splining process, or interference by force fit or shrinkage fit. However, the processing of key seating or spline milling has a disadvantage of involving elaborate work and lowering of the strength of materials, and particularly, such processing is not applicable if a rotating axis comprises a hollow shaft of a thin wall. Furthermore, in case a phase adjustment or dividing between one member such as the rotating axis and the other member is required, the process and assemblage become much more intricate, lowering the efficiency of the operation. In addition, firm coupling is unexpected from the force fit processing due to a danger of a bite, and fixing by shrinkage fit is not applicable to assembly-line production. The coupling method involving such an interference also encounters a problem of lowering of the axis strength in proportion to an increase in interfering intensity.
There is a known coupling which comprises, as shown in FIG. 17, two concentric circular rings a and b having hill-shaped tapers on the faces facing each other with the gap increasing toward both sides, and two wedge-like ring bodies c and d which engage the tapered faces from both sides, being pushed in between the circular rings a and b with a bolt e so that the circular ring bodies a and b dilate out in the radial direction. However, a coupling of this kind is costly in addition to the disadvantage that fitting work requires a great deal of care, because coupling depends on the frictional force between the circular rings a and b and the coupling members, and the ring bodies must be pushed in evenly along the whole circumference to avoid eccentricity.
It is an object of the present invention to provide a low cost coupling of a plain construction.
A further object of the present invention is to provide a coupling which permits an easy phase adjustment and dividing as well as plain fitting.
A still further object of the present invention is to provide a timesaving coupling which requires no grooving processes or the like.
Another object of the present invention is to provide a coupling capable of clutching two members which relatively displace in parallel in addition to the members being turnable relative to each other.